SHARP VC-H680X
Manual de Servicio

NO.24 Hi-Fi TROUBLESHOOTING(2) FLOW CHART NO.26 LINEAR SOUND MODE TROUBLESHOOTING (1) No linear sound recording (Hi-Fi E-E mode is possible) No Hi-Fi sound recording(E-E mode is possible)
NO Check the AUDIO MUTE (H) line between pin

Is there "L" level at pin (99) of IC201? (99) IC651 and pin (21) of IC701.
NO Replace IC651. YES

Check peripheral circuit of IC651 as YES shown in table. Replace IC201. Is there a signal at pin(4) of IC201?

L-ch pins(16),(17),(18),(19) Is the supply voltage 12V fed to pin(2) of
YES YES

R-ch pins(35),(34),(33),(32) NO

YES Check Hi-Fi 5V line. T601? NO

Check PC 12V line.

Check the Bias oscillation circuit(T601,Q602,

Q603) and FE BIAS CTL line. of IC651?
NO Is there signal (Bias + Audio sig.) at pin (6) YES ofT601?

Is there REC FM signal outputted to the Is there signal (Bias) at pin (5) ofT601? pins(21) (24)(ch-1)/pins(21) to (22)(ch-2) of IC651 ? YES
NO Is the supply voltage of 5V fed to pin(25)

YES Check peripheral circuits of T601.

Is there �H� level at pin(29) of IC651? Check AH-MZ harness.
YES NO YES

Check the MH-AM harness and A/C head.

Check or replace the cylinder. Check the Hi-Fi CTL (H) line between pin (29) IC651and pin(54) of IC701.

FLOW CHART NO.27 LINEAR SOUND MODE TROUBLESHOOTING (2) YES
Check the record AGC setting resistor No linear sound playback (Hi-Fi E-E mode is possible) R670 at pin(37) of IC651.
NO Are MH-AA harness and the PB AMP. Replace IC651. Is there a signal at pin(100) of IC201? YES YES YES NO No Hi-Fi sound playback(E-E mode is possible)

47
Replace IC651. YES
YES Replace A/C head.

peripheral parts normal?

FLOW CHART NO.25 Hi-Fi SOUND MODE TROUBLESHOOTING(3) Clean A/C Head.

Is the azimuth height of A/C head properly

adjusted?

Readjust azimuth height.
NO

Is the supply voltage of 5V fed to pin(25) Is there playback envelope signal(about NO 300mVp-p) outputted to the pins(29),(30)

of IC651?

of IC651? NO IC651?

YES A-H.SW.P. signal pin(27) Is there "L" level at pin (99) of IC201? (99) IC201 and pin (21) of IC701.

Check the AUDIO MUTE (H) line between pin

Check peripheral circuit of IC6301 as YES Check the A-H.SW.P. line between pin

NO shown in table.

L-ch pins(16),(17),(18),(19)

Is there a signal at pin(11) of IC201? Replace IC201.
YES R-ch pins(35),(34),(33),(32) (27) IC651 and pin(26) of IC701. NO

YES Is there audio signal inputted at pin(62) Check line between pin (11) of IC201 and

VC-H680X

Replace IC651. IC651? pin (62) of IC651.